diff options
Diffstat (limited to 'net/websocket.lua')
| -rw-r--r-- | net/websocket.lua | 269 |
1 files changed, 269 insertions, 0 deletions
diff --git a/net/websocket.lua b/net/websocket.lua new file mode 100644 index 00000000..3c4746b7 --- /dev/null +++ b/net/websocket.lua @@ -0,0 +1,269 @@ +-- Prosody IM +-- Copyright (C) 2012 Florian Zeitz +-- Copyright (C) 2014 Daurnimator +-- +-- This project is MIT/X11 licensed. Please see the +-- COPYING file in the source package for more information. +-- + +local t_concat = table.concat; + +local http = require "net.http"; +local frames = require "net.websocket.frames"; +local base64 = require "util.encodings".base64; +local sha1 = require "util.hashes".sha1; +local random_bytes = require "util.random".bytes; +local timer = require "util.timer"; +local log = require "util.logger".init "websocket"; + +local close_timeout = 3; -- Seconds to wait after sending close frame until closing connection. + +local websockets = {}; + +local websocket_listeners = {}; +function websocket_listeners.ondisconnect(handler, err) + local s = websockets[handler]; + websockets[handler] = nil; + if s.close_timer then + timer.stop(s.close_timer); + s.close_timer = nil; + end + s.readyState = 3; + if s.close_code == nil and s.onerror then s:onerror(err); end + if s.onclose then s:onclose(s.close_code, s.close_message or err); end +end + +function websocket_listeners.ondetach(handler) + websockets[handler] = nil; +end + +local function fail(s, code, reason) + module:log("warn", "WebSocket connection failed, closing. %d %s", code, reason); + s:close(code, reason); + s.handler:close(); + return false +end + +function websocket_listeners.onincoming(handler, buffer, err) + local s = websockets[handler]; + s.readbuffer = s.readbuffer..buffer; + while true do + local frame, len = frames.parse(s.readbuffer); + if frame == nil then break end + s.readbuffer = s.readbuffer:sub(len+1); + + log("debug", "Websocket received frame: opcode=%0x, %i bytes", frame.opcode, #frame.data); + + -- Error cases + if frame.RSV1 or frame.RSV2 or frame.RSV3 then -- Reserved bits non zero + return fail(s, 1002, "Reserved bits not zero"); + end + + if frame.opcode < 0x8 then + local databuffer = s.databuffer; + if frame.opcode == 0x0 then -- Continuation frames + if not databuffer then + return fail(s, 1002, "Unexpected continuation frame"); + end + databuffer[#databuffer+1] = frame.data; + elseif frame.opcode == 0x1 or frame.opcode == 0x2 then -- Text or Binary frame + if databuffer then + return fail(s, 1002, "Continuation frame expected"); + end + databuffer = {type=frame.opcode, frame.data}; + s.databuffer = databuffer; + else + return fail(s, 1002, "Reserved opcode"); + end + if frame.FIN then + s.databuffer = nil; + if s.onmessage then + s:onmessage(t_concat(databuffer), databuffer.type); + end + end + else -- Control frame + if frame.length > 125 then -- Control frame with too much payload + return fail(s, 1002, "Payload too large"); + elseif not frame.FIN then -- Fragmented control frame + return fail(s, 1002, "Fragmented control frame"); + end + if frame.opcode == 0x8 then -- Close request + if frame.length == 1 then + return fail(s, 1002, "Close frame with payload, but too short for status code"); + end + local status_code, message = frames.parse_close(frame.data); + if status_code == nil then + --[[ RFC 6455 7.4.1 + 1005 is a reserved value and MUST NOT be set as a status code in a + Close control frame by an endpoint. It is designated for use in + applications expecting a status code to indicate that no status + code was actually present. + ]] + status_code = 1005 + elseif status_code < 1000 then + return fail(s, 1002, "Closed with invalid status code"); + elseif ((status_code > 1003 and status_code < 1007) or status_code > 1011) and status_code < 3000 then + return fail(s, 1002, "Closed with reserved status code"); + end + s.close_code, s.close_message = status_code, message; + s:close(1000); + return true; + elseif frame.opcode == 0x9 then -- Ping frame + frame.opcode = 0xA; + frame.MASK = true; -- RFC 6455 6.1.5: If the data is being sent by the client, the frame(s) MUST be masked + handler:write(frames.build(frame)); + elseif frame.opcode == 0xA then -- Pong frame + log("debug", "Received unexpected pong frame: " .. tostring(frame.data)); + else + return fail(s, 1002, "Reserved opcode"); + end + end + end + return true; +end + +local websocket_methods = {}; +local function close_timeout_cb(now, timerid, s) + s.close_timer = nil; + log("warn", "Close timeout waiting for server to close, closing manually."); + s.handler:close(); +end +function websocket_methods:close(code, reason) + if self.readyState < 2 then + code = code or 1000; + log("debug", "closing WebSocket with code %i: %s" , code , tostring(reason)); + self.readyState = 2; + local handler = self.handler; + handler:write(frames.build_close(code, reason)); + -- Do not close socket straight away, wait for acknowledgement from server. + self.close_timer = timer.add_task(close_timeout, close_timeout_cb, self); + elseif self.readyState == 2 then + log("debug", "tried to close a closing WebSocket, closing the raw socket."); + -- Stop timer + if self.close_timer then + timer.stop(self.close_timer); + self.close_timer = nil; + end + local handler = self.handler; + handler:close(); + else + log("debug", "tried to close a closed WebSocket, ignoring."); + end +end +function websocket_methods:send(data, opcode) + if self.readyState < 1 then + return nil, "WebSocket not open yet, unable to send data."; + elseif self.readyState >= 2 then + return nil, "WebSocket closed, unable to send data."; + end + if opcode == "text" or opcode == nil then + opcode = 0x1; + elseif opcode == "binary" then + opcode = 0x2; + end + local frame = { + FIN = true; + MASK = true; -- RFC 6455 6.1.5: If the data is being sent by the client, the frame(s) MUST be masked + opcode = opcode; + data = tostring(data); + }; + log("debug", "WebSocket sending frame: opcode=%0x, %i bytes", frame.opcode, #frame.data); + return self.handler:write(frames.build(frame)); +end + +local websocket_metatable = { + __index = websocket_methods; +}; + +local function connect(url, ex, listeners) + ex = ex or {}; + + --[[RFC 6455 4.1.7: + The request MUST include a header field with the name + |Sec-WebSocket-Key|. The value of this header field MUST be a + nonce consisting of a randomly selected 16-byte value that has + been base64-encoded (see Section 4 of [RFC4648]). The nonce + MUST be selected randomly for each connection. + ]] + local key = base64.encode(random_bytes(16)); + + -- Either a single protocol string or an array of protocol strings. + local protocol = ex.protocol; + if type(protocol) == "string" then + protocol = { protocol }; + end + for _, v in ipairs(protocol) do + protocol[v] = true; + end + + local headers = { + ["Upgrade"] = "websocket"; + ["Connection"] = "Upgrade"; + ["Sec-WebSocket-Key"] = key; + ["Sec-WebSocket-Protocol"] = t_concat(protocol, ", "); + ["Sec-WebSocket-Version"] = "13"; + ["Sec-WebSocket-Extensions"] = ex.extensions; + } + if ex.headers then + for k,v in pairs(ex.headers) do + headers[k] = v; + end + end + + local s = setmetatable({ + readbuffer = ""; + databuffer = nil; + handler = nil; + close_code = nil; + close_message = nil; + close_timer = nil; + readyState = 0; + protocol = nil; + + url = url; + + onopen = listeners.onopen; + onclose = listeners.onclose; + onmessage = listeners.onmessage; + onerror = listeners.onerror; + }, websocket_metatable); + + local http_url = url:gsub("^(ws)", "http"); + local http_req = http.request(http_url, { + method = "GET"; + headers = headers; + sslctx = ex.sslctx; + }, function(b, c, r, http_req) + if c ~= 101 + or r.headers["connection"]:lower() ~= "upgrade" + or r.headers["upgrade"] ~= "websocket" + or r.headers["sec-websocket-accept"] ~= base64.encode(sha1(key .. "258EAFA5-E914-47DA-95CA-C5AB0DC85B11")) + or not protocol[r.headers["sec-websocket-protocol"]] + then + s.readyState = 3; + log("warn", "WebSocket connection to %s failed: %s", url, tostring(b)); + if s.onerror then s:onerror("connecting-failed"); end + return; + end + + s.protocol = r.headers["sec-websocket-protocol"]; + + -- Take possession of socket from http + http_req.conn = nil; + local handler = http_req.handler; + s.handler = handler; + websockets[handler] = s; + handler:setlistener(websocket_listeners); + + log("debug", "WebSocket connected successfully to %s", url); + s.readyState = 1; + if s.onopen then s:onopen(); end + websocket_listeners.onincoming(handler, b); + end); + + return s; +end + +return { + connect = connect; +}; |